The European Commission has identified support for the production and adoption of Open Educational Resources (OER) as a strategic priority, key to addressing the current need to rethink and develop education in a way that is compatible with societal development and development of the skills required in the 21st century. However, in spite of a clear case for framing OER as a contributor to innovation in education, the picture that emerges from recent research reveals several obstacles that need to be overcome for OER to have a substantial impact on education and society. Limited reuse and repurposing of OER by educators, manifested by a tendency to use OER as supplementary rather than primary material, have been attributed to several factors: uneven supply, lack of official policies or incentives for reuse, limited proof of effectiveness and lack of digital and pedagogical skills on the part of educators. The substantial political and philanthropic investment in OER has so far mostly focused on the supply side, but there is now a growing need to increase the uptake of OER by educational practitioners and learners. Fostering reuse of OER and engagement in Open Educational Practice (OEP) is essential if education is to move from the current, static OER landscape to one in which OER and OEP play a major role in a vibrant and sustainable learning ecosystem. The ExplOERer project (pronounced ‘explorer’) promotes OER sustainability through OER adoption and embeddedness in professional practice. The consortium will identify, document and assess obstacles and opportunities, and analyse current practice in the use of OER, including the sustainability aspect. This will be achieved by capitalising on opportunities in cross-boundary contexts in which OER are part of innovation, and by developing education practitioners’ digital and pedagogical skills regarding OER reuse and repurposing. Several types of learning contexts are addressed, including adult education, higher education and the workplace. The project will target the following intellectual outputs: 1) Co-creation of guidelines for training of adult educators on OER reuse. This process will directly involve teachers to increase engagement and improve sustainability. 2) Development of training materials and teacher training in OER reuse and digital skills through an Open Online Course. 3) More dynamic OER infrastructures by means of embedding social networking and gaming mechanics in OER repositories. 4) Stimulation and support for policy development regarding OER uptake through three multiplier events, online and face-to-face expert seminars resulting in policy recommendations. The project adopts a cross-sectoral approach by involving six European partners: three Higher Education Institutions, a Ministry of Education supporting a large OER repository, a private company specialising in OER and social networking/gaming, and a non-profit organisation leading the field in open licensing and open education. The results of the project will be produced in partner languages (EN, GR, NL, PL and SE) and widely disseminated through regional, national, European and international channels.